A nonlinear phase shift of low-power spin waves (SWs) induced by a high-power pumping SW excited both inside and outside the magnonic band-gaps of a magnonic crystal has been studied. The magnonic crystal with spatially periodic thickness is fabricated from an yttrium iron garnet film by chemical etching. The results show that the phase shift of the low-power SWs can be effectively controlled by variation of power level of the pumping SW. This induced nonlinear phase shift is weakened if the pump frequency lies in the magnonic bandgap. The data obtained are well explained by contradirectional coupling of the high-power forward and reflected spin waves. A theoretical model for this effect is presented. Our findings are important for the further progress in SW computing.

中文翻译：

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磁子晶体中泵浦自旋波引起的非线性相移

研究了由在磁子晶体的磁子带隙内外激发的高功率泵浦 SW 引起的低功率自旋波 (SW) 的非线性相移。具有空间周期厚度的磁子晶体由钇铁石榴石薄膜通过化学蚀刻制成。结果表明，低功率SW的相移可以通过泵浦SW的功率水平的变化得到有效控制。如果泵浦频率位于磁子带隙中，则这种引起的非线性相移会减弱。获得的数据可以通过高功率前向和反射自旋波的反向耦合得到很好的解释。提出了这种效应的理论模型。我们的发现对于 SW 计算的进一步发展很重要。